This invention relates to the foliar application of zinc compounds in aqueous solution. More particularly, the invention relates to an improved foliar spray composition comprising a synergistic combination of zinc nitrate, ammonium nitrate and urea in aqueous solution.
The use of micronutrients as fertilizers is experiencing increased use. The elements such as zinc, manganese, boron, copper, molybdenum and iron are fully as important as the primary nutrients, nitrogen, phosphorus, and potassium, although the former are used in much smaller quantities. Agronomic tests in a large number of states have been concerned with establishing where the need for micronutrients exists, comparing sources and carriers and indicating amounts that may be needed.
It is now known that plants growing on soils having pH values over 7.0 usually suffer from lack of zinc availability in the soil due to the presence of various calcium compounds. Therefore, zinc is usually supplied to the plants by foliar means. Unfortunately, foliar application of zinc compositions in accordance with prior procedures is not completely satisfactory because of relatively low absorption of the micronutrient by the leaves of the plant. The best zinc composition previously found has been zinc sulfate combined with a fertilizer solution composed of ammonium nitrate and urea (The Pecan Quarterly, Vol. 7; No. 2, May 1973).